I need to graph the data of a sensor in real time

def graph_sensor(sensor_id):
    import matplotlib.pyplot as plt
    plt.ion()
    fig = plt.figure()
    ax = fig.add_subplot(111)
    fig.show()
    i = 0
    x, y = [], []
    while True:
        x.append(i)
        y.append(sensor_id.value)
        ax.plot(x, y, color='b')
        fig.canvas.draw()
        ax.set_xlim(left=max(0, i-50), right=i+50)
        time.sleep(0.1)
        i += 1